Biolingo- cell membrane and extracellular membrane

Question 1

I am a nucleotide and I have ribose as a sugar. What am I?

Answer 1

RNA

Question 2

What is the definition of Nucleoside?

Answer 2

A componant of a nucleotide that is composed of a sugar group (ribose or deoxyribose), and a nitrogenous base

Question 3

True or False: A nucleoside is a nucleic acid monomer. It is composed of a sugar, a phosphate group and a nitrogenous base.

Answer 3

False. Nucleosides are composed of a sugar and a nitrogenous base but they do not have a phosphate group. In fact, nucleotides are the monomers of nucleic acid.

Question 4

I am a protein that separates parental DNA strands during DNA replication. What am I?

Answer 4

Helicase

Question 5

Which missense mutation in the active site of an enzyme is least likely to affect its enzymatic activity?

Answer 5

Valine, a nonpolar amino acid to Leucine, a nonpolar amino acid

Question 6

Describe DNA.

Answer 6

A nucleotide polymer with a bidirectional structure carrying the genetic information of living organisms and some viruses.

Question 7

I am a DNA fragment newly synthesized on the discontinuous strand. What am I?

Answer 7

Okazaki fragment

Question 8

Complete the following sentence: Replication and transcription begin at specific sites on the chromosome. Replication starts at the ________ whereas transcription begins at the _________ after the promoter.

Answer 8

Origin ; Start site (TSS)

Question 9

Which anticodons corresponds to the codon GUA?

Answer 9

CAU

Question 10

Complete the following sentence: Often an _______ codes for a specific protein domain.

Answer 10

Exon

Question 11

What am I? A type of mutation that can affect multiple genes.

Answer 11

Chromosomal rearrangement

Question 12

What determines where transcription begins?

Answer 12

Promoter sequences on DNA

Question 13

What am I? A protein that reduces the tension in the replication fork.

Answer 13

DNA gyrase

Question 14

Which mechanisms regulate gene expression in eukaryotes?

Answer 14

Methylation of DNA; Activators and repressors that regulate the transcription of a gene; and Micro-RNAs that prevent the production of a particular protein

Question 15

Example of a Watson-Crick base pair in DNA.

Answer 15

Adenine - Thymine; Guanine - Cytosine

Question 16

Describes a genetic mutation.

Answer 16

Permanent modification to the genome of an organism

Question 17

I am a protein that binds to a specific sequence of DNA in order to reduce the transcription of a specific gene. What am I?

Answer 17

Repressor

Question 18

What will be added to the 5’ end of a mature messenger RNA?

Answer 18

A Cap

Question 19

What am I? A point mutation that has no effect on the amino acid sequence of a protein.

Answer 19

Silent mutation

Question 20

Describe transfer RNA.

Answer 20

RNA that brings amino acids to ribosomes during protein synthesis.

Question 21

I am an enzyme that synthesizes ribosomal RNA.

Answer 21

RNA polymerase I

Question 22

I am a nucleotide and I have ribose as a sugar.

Answer 22

RNA

Question 23

True or False: Promoters are required for the initiation of transcription in eukaryotes and prokaryotes.

Answer 23

True, promoters are required in both domains. However their organization is very different between eukaryotes and prokaryotes.

Question 24

I am an enzyme that binds together Okazaki fragments.

Answer 24

DNA ligament

Question 25

How are metabolic pathways regulated in the long term?

Answer 25

By the expression of genes that code for the enzymes needed for this pathway.

Question 26

I am an enzyme that synthesizes messenger RNA.

Answer 26

RNA polymerase II

Question 27

I am a non-coding DNA sequence that protects DNA from shortening during replication/

Answer 27

Telomeres

Question 28

I am a protein that binds to a specific sequence of DNA in order to stimulate the transcription of a specific gene.

Answer 28

Activator

Question 29

Where are chaperone proteins mostly found?

Answer 29

Golgi apparatus and cytoplasm

Question 30

What is a replication model of DNA where parent strands each associate with a new complementary strand.

Answer 30

Semi-conservative model

Question 31

Glycosylation is a potential protein modification in eukaryotes.when does this modification take place?

Answer 31

Post-translation

Question 32

What is an aromatic compound that pairs with a purine to form the double alpha helix of DNA.

Answer 32

Pyrimidine

Question 33

What is composed of a modified guanine and a methyl group attached to the 5’ extremity of mRNAs?

Answer 33

5’ cap

Question 34

What is the step in the dogma of molecular biology in which mRNA is used as a matrix to synthesize proteins?

Answer 34

Translation

Question 35

DNA has a ____ structure that protects stabilizes it.

Answer 35

Helicoidal

Question 36

The central dogma involves _____.

Answer 36

replication, transcription, and translation

Question 37

In the _____ transport vesicles continuously leave the Golgi apparatus to guise with the plasma membrane.

Answer 37

Constitutive secretory pathway

Question 38

What is an epigenetic process resulting in the addition of a methyl group to a cytosine.

Answer 38

DNA methylation

Question 39

During translation, _____________ reads an mRNA molecule and assembles the polypeptides to form proteins according to the sequence read on the mRNA.

Answer 39

Ribosome

Question 40

Explain the difference between the synthesis of a leading strand and a lagging strand.

Answer 40

During synthesis, DNA polymerase can only add nucleotides at the 3' end of the new strands.